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EXTRACTION TECHNIQUE: WATERLESS A/B by geezmeister (format & minor edits by metanoid) [ Back to the Che mi mistry stry Archive Archive ] Wa terless A/B extracti extraction on of p seudo ephe drine drine from tablets Abstract of procedure:
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reduce pills pills to powder form soak 12 hours in non-polar non-p olar solvent solvent rinse with acetone boil in acetone dry thoroughly add base add basing medium medium (OH, acetone) mi mix x thoroughly thorough ly extract with non-polar non- polar solvent solvent gas or extract extract with with aqueous HCl HCl rinse or acetone flash flash recrystalize recrystalize with ISO OH
Standard Procedure: 1)If using 30 mg pills pills w ith red coating, remove the red coa ting. Grind Grind pills pills to po wd er form. Use a morter and p es tle after coffee coffee grinder; grinder; texture texture s hould be a fine fine po wde r and few coffee coffee grinders grinders ge t the pills pills fine enough by themselves. themselves. 2) The The po wde red pill mass should first first be soaked in a non-polar solvent. solvent. Choice Choice o f solvent is dictated dictated by the presence of povidone and/or polyethylene glycol. If povidone is present, mineral turpentine is the solvent of choice; alternatives include xylene, tolulene, mineral spirits. Suggested time: twelve hours. If povidone is not present but polyethylene glycol is present, soak in non-polar solvent for at least six hours. Recommended solvent: xylene, tolulene, mineral spirits. Decant non-polar solvent. 3) Rinse pill mass with dried acetone, discard acetone. If the pills contain an antihistamine, place pill mass in pyex dish, cover cover with two to three times times its volum volume in dried acetone , bring bring temperature up slow ly with hotplate hotplate to a stea dy gentle boil with constant ventilation. No open flame or ignition source may be used. Stir boiling acetone continuously for five minutes, remove from heat, decant acetone. Spread pill mass and allow to dry to complete dryness. 4) Weigh out o ne gram of NaOH for each gram of available available ps eudoe phedrine in the pill mass . Weigh out o ne gram of NaCl for each gram of available pseudoephedrine (rock salt is recommended). Combine and grind in coffee grinder to fine fine p ow der. Take Take care to avoid inhalation inhalation of pow dered NaOH! Mix Mix the combined combined salt and sodium hydroxi hydroxide de with the dry pill pill mass mass and s tir with a glas s rod until the mixture mixture is eve nly and thorou ghly mixed. mixed. 5)With the pill mass/ sodium hydroxide/ salt mixture in a pyrex beaker of sufficient depth to allow the addition of three times times the p ill ill mas mas s volume of non-polar s olvent, add ve ry dry isopro pyl alcohol in small small quantities w hile mixi mixing ng the mass w ith a glass rod; continue continue adding alcohol and stirring stirring until until the pill mass has the consistency of a thin paste. The pill mass should heat slowly during this step. At no time should the mass become too hot to hold comfortably. If the heat rises quickly and beyond comfortable temperature to hold, add non-polar solvent immediately. As long as the temperature doe s not make a quick quick surge, work the pill mass mass for at least te n minutes minutes to insure all portions portions o f the pill pill mass mass have be en e xposed to the base . You You w ill ill observe the color change change of the pill mass mass , most most us ually ually to a medium yellow yellow or light tan/brown tan/brown s hade. This This is e xpected. Dark Dark brown indicates indicates the pres ence o f excess w ater but w ill ill not impede impede the process. 6) Add three times the volume of the pill mass with non-polar solvent. Xylene is recommended. Mix this with the paste very thoroughly, recommended for at least fifteen minutes. Allow to settle, decant the non-polar solvent. Repeat this step twice. The The amount of mix mixing ing and the time time p eriod may be sho rtened for the last tw o non-polar soa ks. Combine Combine the three volumes volumes o f non-polar non-polar solvent solvent use d to extract the the freebas e pse udoephe drine. drine. 7) Wash the non-polar solvent solvent w ith warm distilled distilled wa ter wa sh, cool distil distilled led wa ter was h, and a third third w arm wate r wa sh. Continue wa shing until the w ashe s a re clean. After After the third third w ash, monitor monitor the pH and do not allow it to fall below pH 9. If If necessary to remove excess so dium ions, do a NaOH wa sh of the nonpo lar with a 20% NaOH solution. solution. 8) Extract Extract the pseudo ephe drine drine from the non-pol non-polar ar solvent by gass ing or by aqueous HCl addition addition and evaporation " "
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9) Rinse the collected pseudoephedrine in dry acetone. Dissolve in hot dry isopropyl alcohol and recrystalize with dry acetone a s a s econd so lvent. Repe at the recrystalization. Notes and comments: 1) Pill selection: this process w as developed with gene ric antihistamine tab lets w ith 60 mg ps eudoe phedrine and 2.5 mg tripolidine. It also is e ffective with ps eudoe phedrine s ulphate a ntihistamine tablets with cloropheneramine maleate, and changes the form to the salt form for the reaction. Name brand and generic 120 mg and 240 mg time release pse udoephe drine tablets may be e xtracted w ith the process . Yields for the above average 60- 66 percent of available p seudo ephed rine hydrochloride by w eight. Extraction p rocess yields very clean ps eudoe phedrine HCl. If the pills a re dry matrix formulation s uch as the time rele as e 120 mg caplets , it is very importan t that e very solvent us ed be as dry as possible and that the pill mass not be e xposed to e xcess moisture or allow ed to remain exposed and uncovered. 2) The presoak in non-polar solvent is to remove povidone and mineral turpentine is recommended. Alternatives are so aks in xylene, tolulene , mineral spirits. Minimum twelve ho ur soa k for any solvent but mineral turpentine . If povidone is not listed a nd you are familiar with the p ills and ha ve not e ncountered povidone in them even though unlisted, a soak in a ny of the o ther sugge sted non-polar solvents is done to remove polyethylene glycol. Six hours is sufficient; shorter times may be e ffective but ha ve not be en te sted by the author. PEG should be soluble in any of the nonpolar solvents, but if the pills are the 120 time release formulation (or the "dry matrix" formulation) the author strongly sugge sts xylene be used. 3) The acetone rinse is to rid the pill mass of the non-polar solvent. The following acetone boil is to remove tripolidine or chlorophene ramine maleate . If there a re no antihistamines prese nt in the formula, the acetone boil is unne cessa ry and s hould not be done. Do not bo il the pill mass with the s olvent, or with the s olvent and acetone combined. Rinse the so lvent and the n use fresh a cetone to b oil. Yield seems to be better is the e ntire pill mass is allow ed to dry thoroughly before the a ddition o f base . Drying in the microwave on less than full power is e ffective, although not particularly recommended. Drying in an electric oven at low temperature, not to exceed 150 degrees F if also effective to dry the p ill mass . 4) If the pill mass is in the least clumpy or hard, grind it to powder again before proceeding. NaOH may be used to base . Gram per gram is probably an excess of NaOH, but it doe s e ffect the ba sing. Sodium carbonate has bee n use d with good success and it provides fewe r contaminants to the non-polar solvent that need to be w ashe d out. Baking soda baked completely dry-- 350 degrees for thirty minutes in a shallow dish should be sufficient, yields sodium carbonate. pH Dow n at the po ol store is sod ium carbonate and may also be us ed for the process . Salt is recommende d as an add ition to the lye as it provides a moisture abso rbing subs tance to he lp prevent the lye from abso rbing moisture immediately on pow dering. Lye can be used without grinding it; powde red NaOH s eems to give better performance. 5) The selection of solvents to mobilize the HCl is one of choice. On the antihistamine type pills, MeOH may be used, but is not recommended. Very dry ISO alcohol is one recommendation, although dry acetone seems to work very well. If the pills a re time rele as e o r dry matrix formulation, dryness is es se ntial to yield. Dry acetone is highly recommended. The addition of the solvent should be a little at a time, working the pill mass until a slightly thin paste is achieved. Water, including moisture in a lcohol or acetone , will tend to spee d the basing process up and if NaOH is used it can be come hot to o quickly and damage the pseudo ephe drine. Care sho uld be taken to s elect dry solvents. Working the mass thoroughly is thought to be important to yield. Too much alcohol can impede the a/b process, and the amount used should be carefully tailored to avoid making the pill mass runny and diluting the non-polar solvent with alcohol. 6) Xylene is the author's preferred non-polar solvent for extracting the freeb ase pseud oephe drine a s it is unlikely to contain any significant amount of wa ter straight from the can, or e ven after having bee n use d. It is considered to be the solvent of choice for dry matrix formulations. Tolulene and Mineral Spirits have been used with equivalent success. Naptha is not a recommende d so lvent for this purpose. 7) The w ashe s w ill rid the non-polar solvent o f any color they aquire from the pill mass and e xcess sodium ions. W ash until clean. Save the w ater w ashe s to check for pseudo freebas e that may hitch a ride in the w ater. It can happen. Advantages: wo rks w ith most p ills; safer than solvent boiling techniques; fewer s olvents used ; less odor; pse udoephe drine HCl obta ined is very clean and ha s few er impurities that affect the reaction, contaminate the red phospho rous, or contribute to yield loss . Disadvantages: complex for those unfamiliar with a/b process; risk of damage to the ps eudoe phedrine during the basing process; low yields if done improperly or too much alcohol used; may allow polyethylene glycol or povidone to be e xtracted with the ps eudoe phedrine if proper soa king is not done ; some report limited yields w ith the process. Known to be effective with pills containg the following ingredients: Pse udoephe drine HCl 60 mg Tripolidine 2.5 mg corn starch Flavor
y roxypropy e y ce u o se lactose Magnesium Stearate Polyethylene glycol potato sta rch povidone sucrose titanium dioxide patent no. 5098715 210CA01 __________________________ Pse udoephe drine HCl 60 mg Tripolidine 2.5 mg Hydroxypropyl Methylcellulos e Magnesium Stearate Polyethylene glycol starch titanium dioxide may also contain: cellulose Dioctyl Sodium Sulfosuccinate Hydroxypropyl cellulos e lactose Polysorbate 80 povidone powdered cellulose pregelatinized starch silica gel silicon dioxide so dium sta rch glycolate stearic acid _______________________________ Pse udoephe drine HCl 60 mg Tripolidine 2.5 mg carnuba wax corn starch flavor Hydroxypropyl Methylcellulos e lactose Magnesium Stearate Polyethylene glycol povidone sucrose _________________________________ Pse udoephe drine Hcl 120 mg Candellia Wax Hydroxypropyl Methylcellulos e Magnesium Stearate Microcrystalline Ce llulose Polyethylene glycol povidone titanium dioxide Pse udoephe drine Hcl 240 mg Candellia Wax Hydroxypropyl Methylcellulos e Magnesium Stearate Microcrystalline Ce llulose Polyethylene glycol povidone titanium dioxide
